So bad, she explained, that she's had to tell on-again/off-again ex-fiance Brian Austin Green to give her some space – or else.

"I go bats**t. I've had to say to Brian, 'You have to go and stop talking to me, because I'm going to kill you. I'm going to stab you with some­thing. Please leave,'" she said. "I'd never own a gun for that reason. I wouldn't shoot to kill. But I would shoot him in the leg, for sure."

"I'm afraid of the dark and can't sleep without it," she told the mag. "Yeah. If there's silence and darkness, I can't sleep."

And while the film finds her starring as a demon-possessed high schooler who has to eat boys to survive, she said it was a kissing scene with female co-star Amanda Seyfried that she found the scariest.

"Amanda was not excited about having to do it, but I went for it," she recalled. "Clearly I can't argue that it's not gratuitous, because it is. We both look like children, so it looks like crazy kiddie porn. There's no music – it's just silence and the sound of spit. I feel weird watching it. It was just really uncom­fortable. I felt like I was witnessing some­thing I'm not meant to see."